This invention relates to apparatus for opening the conditioning rolls of a mower conditioner when the header is raised to the transport position. The mower conditioner in which the crop conditioning rolls and the roll opening apparatus is incorporated is of the type having a wheel mounted frame to which is attached a laterally disposed header. The front edge of the header includes a sickle for cutting the crop material as well as means for delivering the harvested material to the nip of the conditioning rolls.
Prior art mower conditioners for use in harvesting hay are disclosed in: Cicci et al, U.S. Pat. No. 4,174,600; Johnson et al, U.S. Pat. No. 3,397,520; and Hurlburt et al, U.S. Pat. No. 3,599,405. In the Hurlbert et al machine there is a wheel supported frame, a header having crop-treating elements thereon pivotally mounted on the frame, link means operatively connecting the header to the frame, and lift means on the frame for pivoting the frame about a horizontal axis. In the machine of Johnson et al, the conditioning rolls are automatically raised by a linkage whenever the header is raised to the transport position. The hay harvesting machine of Cicci et al includes a header which is vertically movable relative to the carrying frame. There is a conditioning roll opening device consisting of a linkage which not only separates the rolls but also serves to stabilize the header when it is in the transport position.
The present invention differs from the prior art in that the rolls are opened by a pair of hydraulic cylinders. The conditioning rolls are separated during the last part of the header lift cycle to allow the machine operator to unplug the mower conditioner without having to leave the tractor seat.